Problems: First days El Capitan was running really smooth (even after I installed some third-party applications). Boot-up super fast. Now, at times MBP stalls....even letters that I type can sometimes appear with a bit of delay,browsing of the web problematic, when moving across the Dock, the icons do not transition well - almost like a replay of a slow movie, plenty of spinning wheels when loading an application (including a simple application such as in-built Dictionary); on boot-up...now takes much longer, sometimes I get even blank white rectangle instead of seeing the "progess bar". Overall the system becomes unresponsive, extremely slow, becomes very difficult to use.

My diagnostics:

kernel_task. It can sometimes run up to 600% of CPU, sometimes 300%..fluctuates...as many as 110 threads open; uses most memory of all apps. When kernel_task is highly active, computer stalls (see activity monitor screenshot). I've noticed that this issue is most likely connected with OVERHEATING (only in the upper left-hand corner of the computer..ie. above motherboard). Placing fingers on the aluminium above the keys (ESC, F1, F2, F3) as well as left of keys TaB, CAPS Lock it feels really hot (almost a burning sensation).The same is true on the back of this area.

If I turn off the computer or open the window and let it cool down, kernel_task problem disappears and system works fine for a while.
FAN: I hardly hear any fan activity during this time (though the fan works generally...sometimes it is audible for a very brief period of time).

All no effect..
The only issue that helps is to cool down the system by shutting it down and waiting (or opening window and letting cold air in).

BATTERY(see screenshot):

- whether AC is on or off, overheating is an issue. But I have another problem: "SERVICE BATTERY" - is a message I get when clicking on the battery icon. Currently it's 100% charged and i get about 2 hours work from it. But it seems the battery might be failing too? (this is a message I got only after I upgraded to El Capitan, on Snow Leopad 14 days ago, there was no problem).
QUESTIONS:
What can be done?What are the causes of this overheating? Why does my fan not kick in more often? Can I somehow get it to work more, and would it provide a solution?
Are the temperatures mentioned above normal? Is my hardware failing?

I need badly to fix this; cannot visit any Genius bar anytime soon (live 2 hours drive away from a store) and do not have a warranty either.

Please help.

Thank you,
kristina

UPDATE!!!:
After i covered partially the vents with the palm of my hand,the RPM of my FAN started spinning and the temperatures of CPU indicators went immediately down. And the system got "speedier" again. Could this be a problem of some sensor? If so, how to fix this?
I actually now installed SMCfancontrol...and it seems it's taking care of business. But can this be a long-term solution?

It sounds like a sensor issue, or a degraded coupling between the heat sink and the CPU. I am not sure why the kernel is maxing out your CPU but that is the cause of the slowdown in the system response - ay max cpu load the system is constantly busy so it can't respond to you typing or opening things etc.

If the system is running at max CPU and the fan is not, it suggests that there is some mismatch there. If you can cause the fan to ramp up by covering the vents by hand that is definitely odd.

I would suspect some hardware issue that has occurred when you reassembled the laptop. I'd double check every connection you made and also see if the problem persists if you put the old drive back in. Also you could try removing the RAM you installed first to see if that makes a difference. Bad RAM usually just causes random kernel panics, not this sort of behaviour but you never know. If you removed or moved the logic board at all then I'd also suspect damage to the thermal paste between the CPU and the heatsink. You could always reapply this to see if it improves your cooling situation.

Your battery probably always needed servicing, but it's only now with the new OS that it displayed that information so prominently. If it only lasts a couple of hours it's probably getting to the end of its life and if you want to keep the computer you probably should replace it. Five years is not a bad run for a lithium battery.

It sounds like a sensor issue, or a degraded coupling between the heat sink and the CPU. I am not sure why the kernel is maxing out your CPU but that is the cause of the slowdown in the system response - ay max cpu load the system is constantly busy so it can't respond to you typing or opening things etc.

If the system is running at max CPU and the fan is not, it suggests that there is some mismatch there. If you can cause the fan to ramp up by covering the vents by hand that is definitely odd.

I would suspect some hardware issue that has occurred when you reassembled the laptop. I'd double check every connection you made and also see if the problem persists if you put the old drive back in. Also you could try removing the RAM you installed first to see if that makes a difference. Bad RAM usually just causes random kernel panics, not this sort of behaviour but you never know. If you removed or moved the logic board at all then I'd also suspect damage to the thermal paste between the CPU and the heatsink. You could always reapply this to see if it improves your cooling situation.

Your battery probably always needed servicing, but it's only now with the new OS that it displayed that information so prominently. If it only lasts a couple of hours it's probably getting to the end of its life and if you want to keep the computer you probably should replace it. Five years is not a bad run for a lithium battery.

Click to expand...

Joe-h2o,
thanks for the response. I actually suspect that the issue with overheating was already with my Snow Leopard - in the last weeks, before I replaced it with a new SSD+ RAM, it was running hot and the fan was kicking in a lot too - it was annoying me and so I decided to upgrade thinking that this would solve the problem (at that time, the HDD was running slow as you'd expect from a HDD, but I had no issues of the sort I am experiencing now).
Regarding the damage I could have done replacing new parts:I think I was pretty careful..replaced HDD with SSD, memory chips..and then unplugged the fan, took it out, cleaned it with a brush...put it in....I also used canned air to dust off the board and the computer in general. Hard for me to imagine that I did damage to the computer but who knows.
Yes, it is odd but once the CPU temperature is up in the 70 degrees (celsia) and I cover the back of my laptop with my hand...(i.e. in the middle the laptop from the other side) the fan kicks in, the temperature immediately sinks to 50s degrees and than there's no kernel_task prolem anymore.
In short, I am fairly positive this has something to do with the overheating issue!
Is there a way how to set the fan manually so that it doesn't have to rely on a sensor and cools the system before it starts acting up? I've tried Macs FAn Control but it didn't start the fan either.....only my hand helped.
This seems to me the only solution now.
I am in a place where I can do much...don't have the old hard-drive with me now (won't have it for 4 weeks) and need to use the computer.
I am also pretty pissed: so it seems my MBP has some serious problem but getting it repaired now..would it make any sense? (and I just invested into a new SSD and RAM)

an update:
I've been now using Mac Control Fan app, and have set it such that based on sensor-value (CPU diode)..my fan starts kicking into higher gear at 46 degrees and I give it a maximum of 65degrees. This keeps the system cool, prevents overheating...and thus far I could use the mac without any problems. Could this be in fact the solution to my problem? I.e. simply use a third-party software to ramp-up fan activity as the system doesn't do it itself?

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